WKPreferences属性
@interface WKPreferences : NSObject <NSCoding>
@property (nonatomic) CGFloat minimumFontSize;//最小字体
@property (nonatomic) BOOL javaScriptEnabled;//是否启用 javaScript
@property (nonatomic) BOOL javaScriptCanOpenWindowsAutomatically;//在没有交互的情况下打开自动打开窗口，默认为NO
@property (nonatomic) BOOL javaEnabled;//是否启用java 默认为NO
@property (nonatomic) BOOL plugInsEnabled; //是否启用插件，默认为NO
@property (nonatomic) BOOL tabFocusesLinks API_AVAILABLE(macosx(10.12.3));
@end
